I've got a G-Tech RR.

I've been having trouble getting accurate RPM readings from my 2 Bonnevilles.
I'm guessing it is because of all the electronic gizmos in the cars.
I tested the GTech on my friends Neon and the rpms worked fine.

I emailed tech support about what would be better a direct feed off the battery or the alternator.... they suggested I try both. (They weren't very helpful)

My question is, isn't the power coming off the alternator different from the battery? .....now if I connect a 12v cig lighter socket to wires coming directly off the alternator and plug in my gtech to that.... could it cause damage?

What have you guys found to get the best readings... battery or alternator?

The battery output is pure & clean DC current. The alternator output is rectified AC current. I would think the battery is the better source for DC power. It depends on how sensitive the instrument that you're using is to any AC ripple riding on top of the DC. Contact the manufacturer of the instrument, they should be able to advise.

It'* very sensitive to interference. If you run it off a splitter, it won't work. Make sure you route your power wire away from anything else (mine is hard-wired now), and don't use a splitter. If you get inaccurate or unstable readings, move the feed or the ground.

I never encountered any problems on my Bonnie in either the overhead power , or the indash lighter.


It did have some issues in the Nova though. Although a 17 year old car isn't always the best for electrical systems, especially one that'* had a sub on it when it'* already barely enough.

I've talked to some GP guys... they said they've had no problems wiring it into the overhead power..... so I might try that too.
Also.... the 91 is creeping up on 15yrs old ......

I thought both of your cars had a sunroof? Or do u have an overhead console with accessory power?